The seat belt laws are considerably more straightforward than this nonsense, hc.
From memory, almost all cars manufactured since 1987 require seat belts front and rear. Goods vehicles from the same date require front seat belts. Minibuses and the like manufactured since about 2000 require likewise. (Older vehicles are fairly easy to spot). If the vehicle is fitted with seatbelts they must be worn except by those crewing emergency vehicles, a driver (or supervisor of a learner driver) which is reversing, a licensed taxi driver or a delivery vehicle making frequent stops (every 50 yards or metres springs to mind as the criterion). Again, all of these are fairly easy to spot. There are also exemptions on medical grounds but these are so few and far between as to be negligible.
By contrast these new regulations require the police to see whether an occupant is smoking, whether he smoking or “vaping”, assess how old the occupants are, whether the car has a sunroof or whether it is one of those “convertibles” that Jayne describes.
I am a little disturbed that the police have decided which laws they will enforce and which they will not. However, this legislation is typical of much which spews forth lately: conceived with the best of intentions but badly thought out by civil servants and politicians with little or no thought for the practicalities of enforcement. And laws that cannot be readily enforced bring the law into disrepute.